Early modifications of cardiac function in preterm neonates using speckle tracking echocardiography

Preterm newborns undergo hemodynamic challenges in the postnatal period. The aim of this study was to investigate myocardial mechanics changes in the postnatal period in preterm infants using speckle tracking echocardiography (STE).

Thirty-nine preterm infants ≤34 weeks' gestation underwent cardiac ultrasound evaluation during the first 96 hours of life. A repeated echocardiogram at 3 weeks of age was performed. Echocardiographic assessment involved left ventricular ejection fraction, mitral E/A ratio, S' and E' velocities, E/E' ratio, tricuspid annular plane systolic excursion (TAPSE), left atrium-to-aorta ratio, ductal diameter and ductal shunt pattern. Left ventricular longitudinal, circumferential and radial strain, apex-basal rotation and twist were measured from the apical 4-chamber and short-axis views using STE.

The mean gestational age was 30 ± 2.7 weeks with a mean birth weight of 1318 ± 485 g. Apical segments demonstrated higher longitudinal strain than basal and mid-ones. In all gestational ages, endocardial longitudinal strain was higher than the epicardial. Epicardial longitudinal strain significantly increased during the first 3 weeks, resulting in the change in basal rotation from counterclockwise to clockwise and thus in the acquisition of twist. Deformation parameters were higher in infants with a hemodynamic significant patents ductus arteriosus.

Echocardiographic assessment of myocardial deformation parameters is feasible in preterm infants. Our data suggest that the maturational process of the myocardium is due to the development of the epicardial layer after birth, which allows the acquisition of the twist.